Table 3.

Standard regression coefficients and correlation coefficient (r values) of stepwise multiple regression analysis for PFTs

		SRC		SRC		SRC	r	P-value
FEV1, %a	PNa	0.183	MLAA	−0.328	TDi	0.491	0.816	<0.0001
MEF75, %a	PNa	0.274	MLAA	−0.396	TDi	0.399	0.859	<0.0001
MEF50, %a	PNa	0.435	MLAA	−0.384	CDi	0.268	0.862	<0.0001
MEF25, %a	PNa	0.462	MLAA	−0.282	TDi	0.226	0.796	<0.0001

Note:

^aPredicted.

Abbreviations: PFTs, pulmonary function tests; SRC, standard regression coefficient; MLAA, low attenuation area at middle zone (%); PNa, airway numbers at peripheral zone; TDi, total zone airway diameter (mm); CDi, airway diameter at central zone (mm); MEF75, maximum expiratory flow at 75% forced vital capacity; MEF50, maximum expiratory flow at 50% forced vital capacity; MEF25, maximum expiratory flow at 25% forced vital capacity.